Large-Eddy Simulation of the Tip Flow of a Rotor in Hover

Ghias, Reza; Mittal, Rajat; Dong, Haibo; Lund, Thomas S.

doi:10.2514/6.2004-2432

Cited by 6 publications

(4 citation statements)

References 20 publications

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“…Extensive tests show that the parallel code achieves reasonably good parallel efficiency for grid sizes that are relevant for the tip-flow simulations. 35…”

Section: E Parallelization Of the Solvermentioning

confidence: 99%

Study of Tip-Vortex Formation Using Large-Eddy Simulation

Ghias

Mittal

Dong

et al. 2005

43rd AIAA Aerospace Sciences Meeting and Exhibit

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The formation of the tip-vortex from a rectangular NACA 2415 wing-tip at a chord Reynolds number of 10000 has been simulated. The simulations employ a parallelized compressible large-eddy simulation (LES) solver that has been developed to simulate wing and rotor tip-flows. The solver employs an immersed-boundary technique in conjunction with a curvilinear structured grid and the dynamic model is used to model the subgrid-scale (SGS) stress terms. A d etailed discussion of the tip-vortex formation and evolution in the near wake is presented.

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“…Extensive tests show that the parallel code achieves reasonably good parallel efficiency for grid sizes that are relevant for the tip-flow simulations. 35…”

Section: E Parallelization Of the Solvermentioning

confidence: 99%

Study of Tip-Vortex Formation Using Large-Eddy Simulation

Ghias

Mittal

Dong

et al. 2005

43rd AIAA Aerospace Sciences Meeting and Exhibit

Self Cite

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“…1 Several works have already shown that LES leads to significant improvements both in the understanding of flow physics and the performance predictions of rotors. 2 Usually, LES is based on the resolution of the filtered Navier-Stokes equations. While effective, this method requires the use of artificial dissipation which limits its accuracy (e.g.…”

Section: Introductionmentioning

confidence: 99%

Application of a lattice Boltzmann method to some challenges related to micro-air vehicles

Gourdain

Jardin

Serré

et al. 2018

International Journal of Micro Air Vehicles

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The demand for micro-air vehicles is increasing as well as their potential missions. Whether for discretion in military operations or noise pollution in civilian use, the improvement of aerodynamic and acoustic performance of micro-air vehicles propeller is a goal to achieve. Micro-and nano-air vehicles operate at Reynolds numbers ranging from 10 3 to 10 5. In these conditions, the aerodynamic performance of conventional fixed and rotary wings concepts drastically decreases due to the increased importance of flow viscous forces that tend to increase drag and promote flow separation, which leads to reduced efficiency and reduced maximum achievable lift. Reduced efficiency and lift result in low endurance and limited payloads. The numerical simulation is a potential solution to better understand such low Reynolds number flows and to increase the micro-air vehicles' performance. In this paper, it is proposed to review some challenges related to micro-air vehicles by using a Lattice-Boltzmann method. The method is first briefly presented, to point out its strengths and weaknesses. Lattice-Boltzmann method is then applied to three different applications: a DNS of a single blade rotor, a large eddy simulation of a rotor operating in-ground effect and a large eddy simulation of a rotor optimised for acoustic performance. A comparison with reference data (Reynolds Averaged Navier-Stokes, DNS or experimental data) is systematically done to assess the accuracy of lattice-Boltzmann method-based predictions. The analysis of results demonstrates that lattice-Boltzmann method has a good potential to predict the mean aerodynamic performance (torque and thrust) if the grid resolution is chosen adequately (which is not always possible due to limited computational resources). A study of the turbulent flow is conducted for each application in order to highlight some of the physical flow phenomena that take place in such rotors. Different designs are also investigated, showing that potential improvements are still possible in terms of aerodynamic and aero-acoustic performance of low-Reynolds rotors.

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“…Large-eddy simulation (LES) has emerged as a tool for studying detailed physics of unsteady separating flows. Ghias et al (2004Ghias et al ( , 2005 performed LES of dynamic stall over a pitching airfoil and tip-flow of a rotor in hover using structured-grid finite-difference methods on curvilinear coordinates at relatively low Reynolds numbers (Re C = 10 4 and 4.5 × 10 4 ). They could successfully compare their computational results with the experimental data of Walker et al (1985).…”

Section: Chapter 2 Literature Surveymentioning

confidence: 99%

Large-Eddy Simulation Analysis of Unsteady Separation Over a Pitching Airfoil at High Reynolds Number

You¹,

Bromby²,

Sifounakis³

2013

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a. REPORT 14. ABSTRACT 16. SECURITY CLASSIFICATION OF:Unsteady flow separation during dynamic stall often leads to unacceptably large vibra-tory loads and acoustic noise, and limit forward flight speeds and maneuverability. To gain a quantitative understanding of the unsteady separation process, large-eddy simula-tion (LES) of turbulent flow over a pitching airfoil at realistic Reynolds and Mach numbers is performed. Numerical stability at high Reynolds number simulation is maintained us-ing an unstructured-grid LES technology, which obeys higher-order conservation principles and employs a globalcoefficient subgrid-scale turbulence model. A hybrid implicit-explicit time-integration scheme is employed to

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Large-Eddy Simulation of the Tip Flow of a Rotor in Hover

Cited by 6 publications

References 20 publications

Study of Tip-Vortex Formation Using Large-Eddy Simulation

Study of Tip-Vortex Formation Using Large-Eddy Simulation

Application of a lattice Boltzmann method to some challenges related to micro-air vehicles

Large-Eddy Simulation Analysis of Unsteady Separation Over a Pitching Airfoil at High Reynolds Number

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